The present invention relates to a containment device for use with medical syringes which provides protection against accidental needle sticks and renders the syringe non-reusable It is well known that several contagious and very dangerous diseases, such as hepatitis and acquired immune deficiency (AIDS), are readily transmitted by contact with residual body fluids found on or within a used medical syringe or needle. For this reason as well as to inhibit drug abuse, most syringes are currently intended for single use. The safe handling of single-use syringes by the user, and those who must dispose of the used syringes, is a matter of urgent concern. In most cases, a protective cap is provided for protection prior to use. However, it is after the needle is used that it is most dangerous. The Center for Disease Control has issued a guide line stating that it is recommended that health- care workers not attempt to replace safety caps after injection due to the fact that many needle sticks occur as a result of this procedure, which may result in exposure to blood-born diseases or other organisms or infections that might be present on a used needle.
There have been many attempts to resolve the problem of accidental needle sticks and unauthorized reuse of syringes and needles. Most of these efforts focused on attempts to effect retraction of the used needle to a position within the syringe or an extension thereof, the placement of a protective sleeve about the needle, or the placement of the syringe and/or needle into a safe container. These attempts, however, have not provided an acceptable solution to the problem. To prevent both accidental needle sticks and unauthorized reuse, a solution should preferably include the following: a mechanism which automatically retracts the needle assembly into a protected environment; a mechanism that is compatible with most existing syringes and needles; a mechanism which if used in combination with existing syringes does not change the capacity or tactile features of the syringe or interfere in any way with the use of the syringe and needle; a device which requires only one-handed operation; a device which would not only retract the needle assembly into a protected environment but also encapsulate and isolate the contaminated needle; a device which would indicate the presence of a contaminated needle; a device, the cost of which would be sufficiently small as to present little or no negative economic reaction; a device of simple construction having a minimum of moving parts and which is readily manufacturable. The protective device of the present invention provides each of these features.